Chemical Forums
Specialty Chemistry Forums => Other Sciences Question Forum => Topic started by: limpet chicken on December 30, 2004, 07:52:52 PM

I am looking to aqquire some scales, I need one capable of weighing micrograms, accurate to at least 5mcg and a seperate scale capable of weighing from milligrams to grams, accurate to a single milligram, and up to thirty grams maximum, shipping to the uk, and paid via paypal, solo card or maestro card.
The top priority is the milligram scale, which I will need regularly, it must be an electric scale, with zero (tare?) function and be accurate to 1mg, I have a small problem however, I am almost totally mathematically illiterate, having had a great deal of problems in school learning even basic elements of addition/subtraction/multiplication without using a calculator :[
So I have a simple question to ask of you people here, I have seen a CHEAP scale, at an online ethnobotanical store (read: psychoactive plant supply shop ;D)
that I know sells good quality merchandise of all sorts, the scale is marked as accurate to 0.01 grams, is that a milligram scale?
Sorry for a stupid question like this, it's not for homework or anything, as I left school a few years ago, and its kind of embarrassing to have to ask something as basic as this, but 0.01 grams is 1mg right? :[
I suppose I can justify a post of a question like this, as I also need advice on a good source for a microgram scale :)
Thanks.

Well, take a look at the decimal point position. Each place represents a tenth, so 0.01 grams means 1/10^{2} grams. Therefore, no, that scale is not in milligrams. It is accurate to 1 centigram, or 10 mg. 1 g = 1000 mg.

Thanks Jdurg, for the answer, I appreciate it, saved me from making a purchase I didn't need, I don't actually understand the decimal notation though, that is how bad I am at anything mathematical.
I can add, devide, subtract and multiply, using a calculator, or count change (usually), but that is the extent of my ability :[

please find below some information for the balance:
1. Analytical balance
Manufacture : A&D
Max weighing capacity up to: 60gm
Readability: 1mg or 0.0001 gm
Price : US$ 2150.
2. Microbalance
Manufacture: Sartorius
Max weighing capacity up to 5.1 gm
Readability : 1 microgram
Price : US$18600.
3. Microbalance
Manufacture: Sartorius
Max weighing capacity up to 2.1 gm
Readability : 0.1 microgram
Price : US$26450.
Wow, it is very expensive.
Please search
www.coleparmer.com/catalog/product_index.asp?cls=113&par=75&cat=1&referred_id=9662k 

please find below some information for the balance:
1. Analytical balance
Manufacture : A&D
Max weighing capacity up to: 60gm
Readability: 1mg or 0.0001 gm
Price : US$ 2150.
Is the readability here a typo, or does readability mean something else?
1 mg = 0.001 g
so a balance accurate to 0.0001 g is accurate to 0.1 mg, right?

Correct. That is why it costs over $2000. ;D